In the case of a natural disaster, for example, a hurricane, all connections to an existing fixed Long Term Evolution (LTE) network infrastructure may be lost. The fixed LTE network infrastructure may include network equipment connected to, for example, cell sites, mobile switching offices and other communication assets of a service provider. When connectivity to the fixed LTE network infrastructure is lost, emergency communication may become impacted. To fill-in during an emergency, deployable LTE infrastructure may be temporarily installed and activated to provide temporary LTE coverage. When activated, the deployable LTE infrastructure is not connected to the fixed LTE network infrastructure and the deployable LTE infrastructure may remain active for an extended amount of time while the fixed LTE network infrastructure is being returned to service. The introduction of a deployable LTE infrastructure to replace the fixed LTE network infrastructure must be secured to avoid compromising devices communicating on the fixed LTE network infrastructure by, for example, introducing vulnerabilities into a process by which the devices mutually authenticate to the fixed LTE network infrastructure.
LTE networks include, among other components, databases such as a Home Subscriber Server (HSS) (also referred to herein as a fixed HSS) that stores user-related and subscription-related information. For example, the fixed HSS is configured to store the international mobile subscriber identity (IMSI) and a related authentication key (K) used to identify and authenticate a subscriber on a communication device (such as a mobile phone and a computer). To prevent unauthorized use of an LTE network infrastructure, the fixed HSS and the information stored therein must be protected.
The 3rd Generation Partnership Project (3GPP) architecture utilizes a symmetric authentication method called Authentication Key Agreement. The authentication key agreement relies on connectivity to the fixed HSS and an Authentication Center (AuC) in the LTE network in order to obtain data that is necessary to successfully complete network entry authentication between the fixed HSS and a communication device requiring access to the LTE network. This model does not work if connectivity to the fixed HSS/AuC is not available, for example, when connection to the fixed LTE network infrastructure is lost.
In circumstances where there is no connectivity to the fixed HSS/AuC, to extend coverage to remote locations and/or to facilitate emergency communications, it may be necessary to deploy an independent deployable LTE system (i.e. an LTE system that is not connected to the fixed LTE network infrastructure). The deployable system may be provided in a mobile environment, for example, on a truck. For the deployable system to successfully complete network entry authentication of communication devices, the deployable system must maintain its own HSS (referred to herein as a deployable HSS) when there is no connectivity to the fixed LTE network infrastructure. The deployable HSS is also configured to store user-related and subscription-related information. However, replication of data from the fixed HSS to the deployable HSS could potentially expose critically sensitive authentication keys to a less secured environment (for example, a mobile deployable system). Accordingly, authentication keys and other user-related and subscription-related information for providing access to the LTE network may be vulnerable to compromise if that data is copied from the fixed HSS to the deployable HSS and access to the data stored in the deployable HSS is compromised. Compromising the deployable HSS compromises the fixed network as well.
Accordingly, there is a need for a method and apparatus for connecting a communication device to a deployable system without compromising authentication keys stored on a database on the fixed LTE network.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.